What is this cheeto-orange mineralization? Options

[CrazySanMan]

I was on a gold claim near Idaho Springs this morning and I came across this outcropping of the orangest rock I've ever seen. The outcropping hasn't been dug and these pieces were sitting on the surface. What kind of mineralization is this intense orange? It's a cheetos or cheese puff orange, very intensely colored. I've seen iron rust that is a dull orange, but nothing like this.

Here's a cell phone picture in the shade, the color is more vivid than it appears here.